:root {
  --ink: #14213d;
  --paper: #f6f4ef;
  --surface: #ffffff;
  --accent: #c8532b;
  --success: #2e7d4f;
  --error: #8a3b1e;
  --muted: #5a6472;
  --border: #d9d4c9;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.55;
  padding: 2rem 1rem;
}

main {
  max-width: 34rem;
  margin: 0 auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 2rem;
}

h1 {
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.75rem;
  margin: 0 0 .5rem;
}

.subtitle { color: var(--muted); margin: 0 0 1.5rem; }

.invoice-summary {
  background: var(--paper);
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
}
.invoice-summary dt { font-size: .8rem; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); }
.invoice-summary dd { margin: 0 0 .75rem; font-size: 1.1rem; font-weight: 600; }
.invoice-summary dd:last-child { margin-bottom: 0; }

label { display: block; font-weight: 600; margin: 1rem 0 .3rem; }
input {
  width: 100%;
  padding: .65rem .75rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1rem;
  background: var(--surface);
  color: var(--ink);
}
input:focus-visible, button:focus-visible, a:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}
input.invalid { border-color: var(--error); }

.field-error { color: var(--error); font-size: .85rem; min-height: 1.2em; margin: .2rem 0 0; }

button {
  margin-top: 1.5rem;
  width: 100%;
  padding: .85rem;
  background: var(--accent);
  color: #ffffff;
  border: none;
  border-radius: 6px;
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
}
button:disabled { background: var(--muted); cursor: not-allowed; }

.disclosure {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1rem 1.25rem;
  font-size: .9rem;
  color: var(--muted);
  margin: 1.5rem 0 0;
}
.disclosure h2 { font-size: .95rem; color: var(--ink); margin: 0 0 .5rem; }
.disclosure ul { margin: .25rem 0 0; padding-left: 1.2rem; }
.disclosure li { margin-bottom: .3rem; }

.status { margin-top: 1.5rem; padding: 1rem 1.25rem; border-radius: 6px; display: none; }
.status.success { display: block; background: #e7f2ea; border: 1px solid var(--success); color: var(--success); }
.status.error { display: block; background: #f7e9e3; border: 1px solid var(--error); color: var(--error); }
.status h2 { margin: 0 0 .4rem; font-size: 1.1rem; }
.status p { margin: .3rem 0; }

@media (max-width: 480px) {
  main { padding: 1.25rem; }
  h1 { font-size: 1.4rem; }
}